Decrease Movie from 60fps to 30fps
This started as a question but how I ended up finding the answer I think I should share since I didn´t find anything related to this subject here.

There´s a way of decreasing from 60fps to 30fps. Today if the movie file is  imported straight on VSE and use 30fps the video will be on on slow motion "off course it´s divided by two times right?".

So the first thing it´s import the file using 30fps:



Now select your movie strip and apply an Speed Control and on the setting use the values:



That´s it now your 60fps file it´s at 30fps and you can continue the editing.